not really a BM question , but there are lot of smart people here so Ill ask. I have a 66 valient , the motor is a slant 6 and the water lines in the block are rusty. I had it flushed by a pro with a machine and he said it was bad. It runs hot unless the weather is cool then its ok , my question is , is there a ggod way to disslove the rust. Was thinking of vinegar , but dont know what it will do when heated.

Be careful about these treatments eating the radiator. Ever see how lemon juice(citric acid) removes the color from a copper bar top? Might eat the radiator also. But then maybe the radiator is the problem...can't get rid of heat.

Vinegar flush is what we did on my 78 Dodge pickup (same straight 6 engine) one of my first tests is drain the fluids and stick a hose in the top of the block then the radiator seeing how the flow is.(With the thermostat out)

On a Side note, I've got a 65 Valiant Convertible, the previous owners weren't good repairers... came with a tiny radiator out of a ford, once we bought an up rated radiator it cooled much better.

The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.

There are a lot of ways, but be careful that you can get it out safely.At worst, there is a way to clean out all these lines, and is a standard recommendation rebuilding an engine.This is the cause of a lot of mystery engine problems.

Kanolabs probably has the right chemical.I use their silikroil for really difficult frozen hardware.

Coke has been recommended for this purpose.Auto trans fluid is a last resort.May penetrate gaskets quite well too.

The risk with clogged galleys is hot spots that you're unaware of, until fatal.This is why few shops will guarantee work on an unrodded block.Some won't even touch one.

It's a lot of trouble with a running engine in the car, so you'll have to make the call.If you're runninbg stock, less risky, of course.That engine is extremely tough though, so worth getting right, even adding fuel injection to.

had 2 qts of vinegar that I bought to take to the playa, drain radiator and put those in and let it run the 3 min then left it overnight and drained it in the morning and went to work. It was cool out about 58 and the car ran 50% better temp wise , on way home at about 82Deg it ran about a 1/5 cooler than normal. So will try with more this week and hope it progresses. thks

tatonka wrote:had 2 qts of vinegar that I bought to take to the playa, drain radiator and put those in and let it run the 3 min then left it overnight and drained it in the morning and went to work. It was cool out about 58 and the car ran 50% better temp wise , on way home at about 82Deg it ran about a 1/5 cooler than normal. So will try with more this week and hope it progresses. thks

Did you drain it at the petcock? If so, drain again by dropping the lower hose. the petcock is a very small hole..

just drained the rad. will take a hose to it this weekend , see many small pieces of rust in the water now , will do another treatment with more vinegar than I used last time . Then alot of flushing , thks again all

Had a slant 5 in my van "Arnold". He gave a lot of good rides..In his past life. He was phone repair.. Then a family toured the US with him.. The mom flagged me down and gave me the spare part that should have gone with Arnold to new home with me. That was 25 tears ago..

Won't cure a blocked line, but evans non-water fluid is a standard for some cars.Stops oxidation.

There are higher efficiency water pumps, which all older engines could use.I use a griffin radiator on my hot running car.A high pressure water pump might be a bandaid.I use one for higher pressure at the cylinder head.